Dräger Savina

Description
100
AutoFlow® (optional)
The AutoFlow function can be activated in the »Settings«
menu.
With AutoFlow, the inspiration flow is automatically adjusted to
changes in lung conditions (C, R) and to the spontaneous
breathing demand of the patient.
Always set the alarm limit »Paw W« as well as VT W in
order to set off an alarm in the event of an increase in
airway pressure or tidal volume VT with change of
compliance.
Typically, the selected inspiration time Tinsp is noticeably
longer than the filling time of the lungs. The inspiration
pressure Pinsp corresponds to the minimum value resulting
from both tidal volume VT and compliance C of the lungs.
Savina automatically controls the inspiration flow so that there
is no pressure peak caused by the resistances of the tube and
the airways. The plateau pressure Pplat varies with changes in
compliance C, as is normal in all constant-volume ventilation
strokes. With AutoFlow, these variations occur in maximum
steps of 3 mbar between ventilation strokes. The plateau
pressure Pplat is automatically limited by the pressure
limitation Pmax = Paw W –5 mbar.
If the tidal volume VT is reached (inspiration flow = 0) before
the inspiration time has elapsed, the patient can breathe in and
out during the remaining inspiration time at the level of the
plateau pressure Pplat.
If the patient breathes in or out during mandatory inspiration,
the plateau pressure Pplat is not changed for this ventilation
stroke. Only the inspiration and expiration flow are adapted to
the patient’s demand. The individually applied tidal volume VT
may differ from the set tidal volume VT in specific ventilation
strokes, but on average over time a constant tidal volume VT is
supplied.
The exceeding increase of the tidal volume VT can be
restricted by the alarm limit »VTi W«. If the set alarm limit is
exceeded one time, Savina sets of an advisory message (!);
if the alarm limit is exceeded three times, Savina sets of a
warning message (!!!). The volume is actively limited to the
alarm limit value »VTi W« by switching over to the PEEP level.
A set inspiration time Tinsp which is shorter than the filling
time of the lungs can be recognized from the flow curve: the
flow at the end of the inspiration time has not yet returned to
zero. The »! Tidal volume low« or »!! Tidal volume low« alarms
indicate that the settings selected do not permit full delivery of
the tidal volume VT. It must now be decided whether the
current condition of the patient permits prolongation of the
inspiration time Tinsp or an increase of the flow acceleration,
in order to apply the set tidal volume VT.
024 37388
Paw
Paw >
Pmax
Flow
without spontaneous breathing with spontaneous breathing
V
T
PEEP
Tinsp Te
1
f
t
t
PPLAT
FlowAcc FlowAcc
FlowAcc
high
FlowAcc
low
033 37388
Paw
Paw >
Flow
without spontaneous breathing with spontaneous breathing
V
T
PEEP
Tinsp Te
1
f
t
t
PPLAT